M&L 3 baby! (spoilers)

[Darking]

I didn't see a discussion thread. This game is pretty fun. Playing as Bowser is waaaay more fun than playing as Mario and Luigi. I'm currently fighting the Dark Star inside of Bowser. It's destroying me.
What exactly trigger's Bowser's Fury mode?

If you get hitted too many times without defending, Bowser will become to Fury mode. In this mode, the attack goes up, but the defense goes down.